This invention relates to a cylinder lock, in particular to a tumbler plate cylinder lock which has a plurality of sheet-like locking members or tumbler plates to perform the locking action.
As is well known, conventional cylinder locks usually employ a plurality of pin tumblers of variable lengths as locking elements which are pressed down from cavities provided in a housing by springs to engage with holes in a cylinder rotatably mounted in the housing. Such a conventional design requires not only many drilling operations to form these cavities or holes, but also makes the positioning of drilling difficult since a great number of holes must be formed to receive these pin tumblers having upper and lower segments. Further, as each cavity or hole in the housing and the cylinder has to be installed with one spring, one upper segment and one lower segment, the assembly process is so delicate that the assembly rate cannot be raised easily. Accordingly, the manufacturing cost of conventional cylinder locks cannot be greatly reduced due to these problems.
The main object of this invention is to provide an improved cylinder lock which has fewer parts to simplify the manufacture and assembly process in order to reduce the manufacturing cost thereof.
Another object of this invention is to provide a cylinder lock in which a plurality of sheet-like locking members or tumbler plates, each two being arranged in a pair, are provided to effectively inhibit the lock device from being picked or opened without the use of a proper key.